The present invention relates to a reciprocating process of laying any profile piece on a given supporting base consisting of any sheet, plate, or film material in one or several layers, in order to plot on the said base and/or to cut from it the contour of said pattern profile pieces, while arranging said profile pieces on the base so as to minimize the loss of the base material, eventually taking into consideration such parameters as, for instance, those inherent to the nature of the material or to the intended purpose of the plotted and/or cut pieces.
The invention more particularly applies to the cutting of patterns in the leather industry and especially the shoe industry, but it may as well apply to any other fields where there is a problem of the optimum arrangement of varied and more or less elaborated profile pieces on a base of whatever character in view of plotting and/or cutting said profile pieces.
In the shoe industry, the cutting of parts with a sophisticated contour is mostly achieved by means of hollow punches. This approach gives the operator the control of the positioning of his tool onto the skin to be cut out, for small enterprises however it is expensive and increases the response time of the firm by reason of the time required for the preparation of the tools.
Over the recent years, new technological approaches have been introduced in leather cutting procedures, which tend to supersede hollow punches.
Thus, two new cutting processes: laser beam and fluid jet respectively have been developed, and, in association with computer techniques, they feature the utmost flexibility, thereby permitting a firm to control a variety of cutting out and/or plotting requirements over a very short period.
However the process of positioning the pattern pieces on the leather or skin is thereby made complex and expensive and no satisfactory solution has been offered to date.
According to a first lay technique known already, a reference skin is covered by hand by the cutting operator with several paper or cardboard templates. After the skin has been covered in this way, it is scanned and stored into a computer memory which subsequently controls the cutting of the skin in compliance with the stored data. This approach is time-consuming, not easily practicable and it requires the preparation of templates.
According to a more sophisticated and computerized technique a computer handles every skin in accordance with the skin defects and, in the surface available, it arranges the positioning of the various patterns previously entered in the computer memory, next, it initiates the cutting out of the skin.
Unfortunately this both complex and expensive system has never being developed to a reliable operational condition and it cannot be utilized in the industry.